The processing of textile yarns or fibers usually includes the very important step of drafting or texturing, depending on the type of fibers or yarns being processed. The older and more conventional processing systems utilized discontinuous natural or synthetic fibers which were treated in either single or double long draft apron systems. In this process, drafting aprons were used to draw out the bundle of fibers into greater length and smaller cross-sections, thus creating a strand having uniform properties.
When processing continuous filament synthetic yarns, texturing mechanisms are utilized, and the yarns are passed between texturing aprons which usually impart a twist to the yarns while drawing them out in a manner similar to the drafting system. The yarns are then heat set in a state imparted by the aprons, resulting in increased bulk and improved surface effect that promotes the processing of the yarns into fabrics.
A common problem with existing aprons, whether employed as texturing aprons or drafting aprons used in either the single or double long draft apron system, is the tendency for such aprons to stretch after extended use. Further, conventional aprons, whether new or stretched, have a further problem in tracking precisely during operation thereof in an associated system. In an effort to prevent such undesirable stretching, aprons proposed heretofore have utilized helically wound substantially inextensible cords and/or woven fabric layers embedded in a matrix material. However, such cords and/or fabric layers are expensive and do not provide uniform tensioning of the apron across its width.